The goal of this pilot investigation is to examine the feasibility of a large, longitudinal, community based study of incident Alzheimer's disease in a biracial population in the metropolitan Chicago area. Using U.S. census data, the pilot will examine the demographic characteristics of all communities in the metropolitan Chicago Standard Metropolitan Statistical Area for general suitability for the planned study. Communities with the most favorable demographic features will be investigated in greater detail. This will include identification of community leaders and organizations and of the sources of health care used by community residents. Potential support for the study from community leaders and health care providers will be assessed. In the communities most suited to the study, residents' willingness to participate will be directly assessed with brief structured, in home interviews. Brief tests of cognitive function suitable for population interviewing and protocols for detailed clinical assessment for dementing illness will be tested for acceptability in small samples of community residents. The results of the pilot will then be used in the design of a proposed full-scale study.